Intake manifold of vertical multicylinder engine

Patent metadata

Field	Value
Publication number	US-10612498-B2
Application number	US-201514842314-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Sep 30, 2014
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

There is provided an intake manifold of a multicylinder engine capable of facilitating homogenization of concentration distribution of EGR gas in intake air and distribution of EGR gas into respective cylinders. The intake manifold is configured such that an EGR gas guide portion is provided in an intake air introducing sleeve portion, the EGR gas guide portion includes an upstream EGR gas release port and a downstream EGR gas release port, the upstream EGR gas release port is provided on a side of a passage outlet of an EGR gas introducing passage, the downstream EGR gas release port is provided on an opposite side of a central portion of the intake air introducing sleeve portion from the upstream EGR gas release port, and the EGR gas introduced from the passage outlet of the EGR gas introducing passage into the intake air introducing sleeve portion is released from both of the upstream EGR gas release port and the downstream EGR gas release port into intake air passing through the central portion of the intake air introducing sleeve portion.

First claim

What is claimed is:

1. An intake manifold of a vertical multicylinder engine comprising:
a manifold main body; an intake air introducing sleeve portion; and an EGR gas introducing passage, and
configured such that when a longitudinal direction of the manifold main body is defined as a front-back direction, a passage outlet of the EGR gas introducing passage is provided on a front side or a back side of a sleeve portion peripheral wall of the intake air introducing sleeve portion and EGR gas is introduced from the passage outlet of the EGR gas introducing passage into the intake air introducing sleeve portion,
wherein the intake manifold is configured such that an EGR gas guide portion is provided in the intake air introducing sleeve portion, the EGR gas guide portion includes an upstream EGR gas release port and a downstream EGR gas release port, the upstream EGR gas release port is provided on a side of the passage outlet of the EGR gas introducing passage, the downstream EGR gas release port is provided on an opposite side of a central portion of the intake air introducing sleeve portion from the upstream EGR gas release port,
the EGR gas introduced from the passage outlet of the EGR gas introducing passage into the intake air introducing sleeve portion is released from both of the upstream EGR gas release port and the downstream EGR gas release port into intake air passing through the central portion of the intake air introducing sleeve portion;
the manifold main body has a box-shaped configuration having no branch portion and extending along a lateral side surface of a cylinder head, the manifold main body having an entire surface facing the cylinder head defining a lateral opening and a ceiling wall out of four walls that surround the lateral opening from top, bottom, front and back, the ceiling wall being long in the front-back direction and being located closest to the EGR gas introducing passage;
wherein the intake air introducing sleeve portion and the EGR gas introducing passage are provided in the ceiling wall of the manifold main body and the intake air introducing sleeve portion is led out from the ceiling wall of the manifold main body;
wherein, when viewed in a direction extending along both the lateral side surface of the cylinder head and a central axis of the intake air introducing sleeve portion, both the central axis of the intake air introducing sleeve portion and a central axis of the EGR gas introducing passage are in a place where the central axis of the intake air introducing sleeve portion and the central axis of the EGR gas introducing passage overlap the manifold main body having the box-shaped configuration and extending along the lateral side surface of the cylinder head; and
wherein the EGR gas introducing passage is formed integrally with the ceiling wall provided on an upper side of the manifold main body, and, when a direction perpendicular to the front-back direction and a vertical direction is defined as a lateral direction, a cross-section of the EGR gas introducing passage is formed in a horizontally long shape along the ceiling wall provided on the upper side of the manifold main body, when viewed from a visual line in the front-back direction extending along the central axis of the EGR gas introducing passage.

2. The intake manifold of a vertical multicylinder engine according to claim 1 ,
wherein the EGR gas guide portion includes a guide bottom wall and a guide peripheral wall, the guide bottom wall bulges into the intake air introducing sleeve portion in a direction intersecting a central axis of the intake air introducing sleeve portion, the guide peripheral wall is led out from an opening edge portion of an intake air passing port surrounded with the guide bottom wall toward an inlet of the intake air introducing sleeve portion, the upstream EGR gas release port and the downstream EGR gas release port open on the guide peripheral wall, and an EGR gas guide clearance sandwiched between the sleeve portion peripheral wall of the intake air introducing sleeve portion and the guide peripheral wall is formed between the passage outlet of the EGR gas introducing passage and the downstream EGR gas release port.

3. The intake manifold of a vertical multicylinder engine according to claim 2 ,
wherein an end portion of the EGR gas guide clearance on a side of the inlet of the intake air introducing sleeve portion opens in the intake air introducing sleeve portion.

4. The intake manifold of a vertical multicylinder engine according to claim 3 ,
wherein the upstream EGR gas release port opens with a smaller opening area than the downstream EGR gas release port.

5. The intake manifold of a vertical multicylinder engine according to claim 3 ,
wherein the EGR gas guide portion includes a single upstream EGR gas release port and a single downstream EGR gas release port.

6. The intake manifold of a vertical multicylinder engine according to claim 3 ,
wherein a wall out of walls that surround the EGR gas introducing passage from top, bottom, right and left, the wall being furthest apart from the ceiling wall of the manifold main body when viewed in a direction extending along the central axis of the EGR gas introducing passage, is a passage ceiling wall of the EGR gas introducing passage, and
the passage ceiling wall provided on an upper side of the EGR gas introducing passage is inclined as gradually approaching toward the ceiling wall provided on the upper side of the manifold main body, from a starting end side of the EGR gas introducing passage to the EGR gas guide clearance.

7. The intake manifold of a vertical multicylinder engine according to claim 6 ,
wherein the upstream EGR gas release port opens with a smaller opening area than the downstream EGR gas release port.

8. The intake manifold of a vertical multicylinder engine according to claim 2 ,
wherein the upstream EGR gas release port opens with a smaller opening area than the downstream EGR gas release port.

9. The intake manifold of a vertical multicylinder engine according to claim 2 ,
wherein the EGR gas guide portion includes a single upstream EGR gas release port and a single downstream EGR gas release port.

10. The intake manifold of a vertical multicylinder engine according to claim 1 ,
wherein the upstream EGR gas release port opens with a smaller opening area than the downstream EGR gas release port.

11. The intake manifold of a vertical multicylinder engine according to claim 1 ,
wherein the EGR gas guide portion includes a single upstream EGR gas release port and a single downstream EGR gas release port.

Assignees

• Kubota Kk

Inventors

• Ishihara Mutsuhisa
• Nakamura Yasushi

Classifications

• F02M26/42

  having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders · CPC title

• F02M35/112

  for engines with cylinders all in one line · CPC title

• F02M35/1045

  characterised by the charge distribution between the cylinders/combustion chambers or its homogenisation · CPC title

• F02M35/104

  Intake manifolds · CPC title

• F02M26/19

  Means for improving the mixing of air and recirculated exhaust gases, e.g. venturis or multiple openings to the intake system · CPC title